Devices for cleaning vehicular exhaust gas, in particular diesel exhaust particle filters, may include a filter body (also called substrate or monolithic body) which has gas flowing through it and an inflow side end face and an effusion side end face, as well as a circumferential wall, a housing surrounding the filter body, as well as ring segment type, axially compressed clamping members provided on the outer edge of at least one end face between the latter and the housing.
Devices of this type are, for instance, catalytic exhaust gas cleaning devices, or filters for diesel exhaust particulates, to which the invention refers in particular.
The filter bodies may be composed by extruded, one-piece, monolith-like individual bodies which are glued together and, in most cases, are of SiC material. These elongated individual bodies are available on the market mainly with a square cross section. The individual bodies have a front face with numerous inlet channels starting from one front face on the inlet side and ending in a blind hole. The inlet channels usually have a square cross section and are arranged in a honeycomb manner. Immediately adjacent to the inlet channels, outlet channels are provided which are not in an immediate flow connection with the inlet channels. The outlet channels are also of square cross section and are arranged in a honeycomb manner. However, the outlet channels start from the opposite front face (outlet side) and end in blind holes. The exhaust gas flows from the inlet front face into the numerous inlet channels and diffuses through the adjacent walls into the outflow channels. Soot particles are retained within the inflow channels. Catalytic converters for exhaust gas have corresponding constructions and comprise a filter body with a catalytic coating.
A generic device is known from EP 1 236 872 A1. Here, a one-piece filter body is mounted in the housing by a ring of warp-knitted or woven filaments being positioned at the two axial ends of the filter body, more specifically at the transition between the end faces and the circumferential wall, and being clamped between the filter body and the housing. It is via the two rings of warp-knitted or woven filaments that the force is transferred which is necessary for supporting the ceramic filter body usually structured like a honeycomb. The ring of warp-knitted or woven filaments has protrusions extending in front of the associated end face. These portions are termed clamping members in the following.